1. Field of the Invention
Embodiments of the present invention generally relate to a snowmobile assembly. More specifically, embodiments of the present invention relate to an improved snowmobile assembly yielding increased energy absorption in its suspension, improved handling, optimized engine positioning and lower center of gravity.
2. Description of the Related Art
Performance characteristics of snowmobiles, including the comfort of the ride, depend upon a variety of systems and components, including the snowmobile suspension design, and the length and weight of the snowmobile. Typically, a snowmobile suspension includes two systems, a front suspension system for the skis and a rear suspension system for the track.
The rear suspension of a snowmobile supports an endless track driven by the snowmobile engine to propel the machine. The track is supported beneath the vehicle chassis by a suspension that is designed to provide a comfortable ride and to help absorb the shock of the snowmobile crossing uneven terrain. Most modern snowmobiles utilize a slide rail suspension which incorporates a pair of slide rails along with several idler wheels to support the track in its configuration and to slide inside the rubber drive belt when the suspension is in a compressed state. The slide rails are generally suspended beneath the chassis by a pair of suspension arms, each arm being attached at its upper end to the tunnel of the snowmobile, and at its lower end to the slide rails. The mechanical linkage of the slide rails to the suspension arms and to the snowmobile chassis typically is provided with springs and one or more shock absorbers inside the rubber track, the springs being loaded to urge the slide rails downwardly away from the snowmobile chassis, and the shocks providing dampening forces for ride comfort.
A variety of configurations of suspension arms, springs, shocks, and shock rods have been utilized to alter the characteristics and feel of the ride given by a particular suspension system. For example, a snowmobile track suspension may have a pair of generally parallel suspension arms connecting the slide rails to the snowmobile chassis. In such a configuration, the lower end of the rear suspension arm has a pivot mount that is movable longitudinally of the frame. When this pivot is located at its forward most portion of longitudinal movement (i.e., at the forward end of a longitudinal slot), the suspension arms form a parallelogram with the snowmobile chassis and the slide rails so that upward movement of the front suspension arm is transmitted through the slide rails to the rear suspension arm, causing the slide rails to move upward in an orientation that is generally parallel to the snowmobile chassis. Thus, the front end of the slide rails cannot move higher than the back end of the slide rails. The longitudinal slot into which the lower end of the rear suspension arm is pivotally mounted, however, permitting the back end of these slide rails to move higher than the front end of the rails. These designs are generally considered to be the reason why current suspension systems produce a comfortable ride as bumps in the terrain are encountered.
In many known systems, the front suspension arm is limited to minimal suspension travel because of a plastic driver fixed in the snowmobiles tunnel, over which the rubber drive track must travel. Thus, the amount of travel for existing snowmobile suspension systems are limited to about 2 to 6 inches for the front suspension arms of true vertical displacement and about 6 to 9 inches for the rear suspension arms of true vertical displacement.
However, while these designs may be sufficient for certain conditions, there are significant limitations which snowmobile riders encounter on a frequent basis, for example, when travelling over moguls or on bumpy terrain. Thus, there is a need for an improved snowmobile suspension capable of increased energy absorption in its suspension, improved handling, optimized engine positioning and lower center of gravity.